1825290821 has 4 divisors (see below), whose sum is σ = 1825418700. Its totient is φ = 1825162944.

The previous prime is 1825290809. The next prime is 1825290829. The reversal of 1825290821 is 1280925281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1280925281 = 433 ⋅2958257.

It can be written as a sum of positive squares in 2 ways, for example, as 412658596 + 1412632225 = 20314^2 + 37585^2 .

It is a cyclic number.

It is not a de Polignac number, because 1825290821 - 2¹⁸ = 1825028677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1825290829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39386 + ... + 72123.

It is an arithmetic number, because the mean of its divisors is an integer number (456354675).

Almost surely, 2^1825290821 is an apocalyptic number.

It is an amenable number.

1825290821 is a deficient number, since it is larger than the sum of its proper divisors (127879).

1825290821 is a wasteful number, since it uses less digits than its factorization.

1825290821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127878.

The product of its (nonzero) digits is 23040, while the sum is 38.

The square root of 1825290821 is about 42723.4223933430. The cubic root of 1825290821 is about 1222.1111036136. Note that the first 4 decimals are identical.

The spelling of 1825290821 in words is "one billion, eight hundred twenty-five million, two hundred ninety thousand, eight hundred twenty-one".